This symposium paper examines policy formation in early childhood education in terms of the functions, consequences, and implications of ideological conflicts. A definition of ideology is presented, and reasons are given in the context of this definition as to why an unreliable data base is the cause for current ideological battles in early childhood education. Ideological camps (Piagetians, Behaviorists, neo-Freudians, Open Educators) are viewed as tending to avoid evidence counter to their beliefs, primarily by rejecting each other's "data" as inadmissible evidence. Therefore, it is concluded that policy decisions cannot be made on the basis of evidence, for what we are willing to accept as evidence is a function of our ideologies. (CS)